Electricity meter



Dec. 27, 1927.

v F. HOLDEN ELECTRICITY METER I Filed April 22. 1926 Patented Dec. 27, 19270 v UNITED STATES PATENT omen;

FRANK HOLDEN, OF HAMPSTEAD, LONDON, ENGLAND, ASSIGNOR O1" 0NIE-HA3LF TO MEASUREMENT, LIMITED, OF LONDON, ENGLAND.

ELECTRICITY METER.

Application filed April 2a, 1926, Serial No. 103,921, and in Great Britain April 25, 192.5.

This invention relates to electricity meters and more particularly to the type of meter in which a conducting bell or armature rotates in a body of mercury while being acted upon by a magnetic field.

The object of the present invention is to provide an improved construction of this type of meter which will enable the magnet system to be made as small as possible thus permitting of theemployment of a small rotating armature and resulting in economy in the use of mercury and other materials.

The invention consists in imbedding or moulding the magnet system in the material forming the walls of the chamber which contains the mercury and subsequently magnetizing the magnet system after assembly of the parts. I y

The invention also consists in other details hereinafter described or indicated.

The accompanying drawings illustrate modes of carrying out the invention.

Figure 1 is a plan showing the magnet system and mercury chamber constructed and arranged in accordance with one mode of carrying out the invention, and

Figure 2 is a sectional elevation thereof.

Figure 3 is a plan view of a second mode of carrying the invention into effect,

Figure 4 is a plan view of athird mode of carrying the invention into effect and Figure 5 is a crosssectional view thereof along the line 22.

In carrying my invention into effect in one convenient manner I form the external magnet ring, a, of, say, tungsten steel which may, for example, be formed from a bar of steel of correct length bent round and acetylene Welded at the butt joint, the ring so formed after being hardened having its i11- ternal surface groimd to the correct dimensions.

The internal magnet 6 is formed of high grade cobalt steel and the two members a and b are imbedded ina cup-shaped mould c of some suitable inouldable insulating material such, for example, as that sold under the name balrelite, the members a and Z) being spaced apart to form an annular mercury chamber d.

To permit of magnetization of the whole magnetic system when the same has been thus assembled I provide means whereby an electric current may be made to flow so as to link with the magnetic system. In one convenient arrangement this may be elfected by providing a plurality of holes e in the moulding material arran ed upon each side of the internal magnet so that a conductor or conductors may be passed therethrough for the purpose of conveying the magnetizing current, and after the magnetizing operation has been completed theconductors may be removed and the holes may then be closed in any convenient manner as, for example,

by screws, plugs or the like or by a plate covering them externally. i

Referring now to Figure 3, in place of providing a number of apertures e as shown in Figures 1 and 2 I may arrange a number of conducting pins or plugs e in the material forming the cup so that they are moulded therewith, these pins or plugs being utilized in connection with any form of jig or other contrivance adapted to complete the magnetizing circuit, and it will readily be understood that the larger the magnetizing current available the fewer will be the number of holes or plugs required.

For the purpose of enabling a cover plate to be attachedafter completion of the operations hereinbefore described I may mould in With the cup a series of studs 7 by which such cover plate may be secured.

In, Figures 4 and 5 I have shown a third mode of carryingmy invention into effect in a particularly convenient manner. In carrying my invention into effect according to this modification in its application to an electricity meter having an external magnet ring a with an internal permanent magnet Z situated therein I may form the external ring magnet from a bar of tungsten steel of suitable cross-section and bent into the form of a ring having its lap joint acetylene welded while the internal magnet 22 is preferably formed of cobalt steel.

The chamber containing the magnet system is formed in two parts of some suitable moulded insulating material, one part a being formed as a central cylindrical core having the magnet Z) embedded therein, while the other part (Z of the chamber is formed as a surrounding cylindrical part having the external ring magnet a embedded therein,

In the figures illustrated the two parts of the chamber are so formed that the central core 0 is entered into the outer part at from the top and fits into the bottom of the said outer part but clearly the construction may til till

be such that the central core portion may be entered from the bottom. In either event the two parts are such as to leave an annular space e for the copper cup or bell and for the mercury, and they may either be held netized after the assenibly of the parts.

The invention is not to be limited to the forego ng details which are given by ay of illustration only as I may vary the materials employed in forming the various parts or my improved mercury cup and magnet sys tem and I may adopt any suitable means for permitting the magnetizing otithe magnet system to be effected; after the assembly of the parts depending upon. any practical requirements that may have to be fulfilled.

Having now described my invention What I claim as new and desire'to secure by Letters Patent is y 1. An electricity meter'of the kind referred to comprising a mercury chamber formed with Walls of mouldable insulating material, an internal magnetizable bar and an external magnetizable ring embeddedin said Walls and means permitting said bar and said ring to be magnetized a'l'te assembly oi the parts. 7 p i y 2. An electricity meter of the kind referred to comprising a mercury chamber formed with Walls of mouldable insulating said Walls and means permitting an electric circuit to be arranged so that aeurrent flowing therethrough Will link with the bar and ring in order to magnetize the same after assembly oi the parts.

3. An electricity meter of the kind referred to comprising a mercury chamber formed of mouldable insulating material, an internal magnetizz'ible bar and an external magnetizable ring embedded in the Walls of. said mercury chamber, the latter having apertures therethrough through which a conductor maybe passed to convey electric current for the purpose of magnetizing the barand ring after assemblyot' the parts.

l. An electric measuring instrument of the kind referred to comprising a mercury chamber formed with inner and outer walls of mouldable insulati ig material with an annular space thcrcbetween, an internal magnet embedded in the inner Wall portion and an external magnet ring embedded in the outer wall portion.

5. An electric measuring instrument oil": the kind referred to comprising a mercury chamber -tormed from a central core of moulded insulating material andan outer cylindrical portion also oi moulded insu lated material into which said core portion is fitted so that an annular space is left between said portions, an internal magnet embedded in the core and an external magnet ring embedded in the outer cylindrical portion. a p y a y In testimony whereof I have signed my name to this specification.

FRANK HOLDEN.

ill] 

